Passivhaus: Affordable+Necessary

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Transcript of Passivhaus: Affordable+Necessary

?SINGLE FAMILY RESIDENTIALPH = 56% reduction over average US EUI source of 76.6.Courtland Place Passive Project, Dan Whitmore::walls: R-55::floors: R-20 to 49::roof: R-76::windows: U=0.18 to 0.22also known as Passive Housewell-provenPASSIVHAUSpredictablecost-effectiveOK. What IS Passivhaus?A Passive House is a very well-insulated, virtually air-tight building that is primarily heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized. Any remaining heat demand is provided by an extremely small source. Avoidance of heat gain through shading and window orientation also helps to limit any cooling load, which is similarly minimized. An energy recovery ventilator provides a constant, balanced fresh air supply. The result is an impressive system that not only saves up to 90% of space heating costs, but also provides terrific indoor air quality and superior comfort.Only Three RequirementsSpace heating or cooling demand must be less than 4.75 kBtu/square foot/year.

Primary energy demand must be less than 38 kBtu/square foot/year.

Less than 0.6 air changes per hour when measured at 50 Pascal with a blower door test.PHPPPassivhaus Planning PackageHow is it done?low surface to volume ratioadditional insulationhigh performance windowsno thermal bridgescareful attention to air sealingheat recovery ventilationoptimized with PHPP softwarePassivhaus is NOT...Passivhaus is not "passive solar."Passivhaus is not "net zero energy."Passivhaus is not just houses.Passivhaus is not a comprehensive set of green strategies.Passivhaus is not "net zero energy."Passivhaus is not "passive solar."Passivhaus is not a comprehensive set of green strategies.Passivhaus is not just houses.AdaptationSufferingMitigationNOTLEED PlatinumWHYThat's measured according to the German TUV method (DIN-277), which measures to the inside of the walls, doesn't count the area of interior walls, storage areas or stairs above a certain height. For many buildings this means a net area ~20% less than the gross square footage. Therefore Passivhaus heating demand measured against GSF actually ends up ~20% less than 4.75 kBTU/SF/year.Primary energy (aka "source" energy") includes heating, cooling, appliances, plug loads—everything. In Passivhaus, an energy factor is applied to account for losses in generation and transmission.Just to give you an idea: An old house might test at >16.0 ACH@50, a typical new house more like 5.0 ACH@50, and an energy-efficient house built with attention to air sealing in the 2.0 ACH@50 range. Getting to 0.6 ACH@50 requires careful detailing by the designer and rigorous follow-through by the builder.With such a tight building proper ventilation is a must. Code-required ventilation rates for standard houses assume a much leakier envelope, and require a lower amount of ventilation than Passivhaus does. They assume that extra "fresh" air is coming in through the cracks...like through the floor from the crawlspace...down through the insulation in the attic...around the edges of the windows....(Ick!)

Of course, in a Passivhaus you can open the windows too. It's not THAT German.In the last 20 years, 25,000 to 30,000 Passivhaus buildings have been built in Western Europe.Passivhaus will be code in the EU in 2012, and code in the UK in 2013.populationCO2 emissionsbusiness as usual --> fully engagedOur response to climate change will involve three aspects:We decide now what proportion of each we (and subsequent generations) will experience.SINGLE-FAMILYUS EUI, source: 76.6 PH = 56% reductionFarm + Forest Passivhaus, HARRISON architectsEatonville, WA::walls: R-48::floors: R-48::roof: R-79::windows: U=0.19SINGLE-FAMILYUS EUI, source: 76.6 PH = 56% reductionBonaparte Cabin Passivhaus, HARRISON architectsOkanogan Highlands, WA::walls: R-69::floors: R-96::roof: R-102::windows: U=0.11eg: reduction of carbon emissions through:energy conservation (Passivhaus, Living Building Challenge)distributed clean energy production (solar, wind, geothermal)urban density (reducing transportation energy)eg: responding to climate disruption by:relocation of affected populationsseawalls, dikes, flood controlfood crop changesdevelopment of vaccineseg: affects of unmitigated climate disruption:climate refugeesstorms, floodingfaminediseaseeconomic impacts of all of the aboveRob Harrison AIAThe gross square footage of the building is 52,000 SF.The current energy use index (EUI) is 16.The treated floor area (based on the German DIN 277-2 method) is 39,050 SF.The limit in Passivhaus for Primary Energy is 38 kBTU/SF/yr.

In Passivhaus, an "energy factor" is applied to various forms of energy to account for generation and transmission losses. For electricity, this factor is 2.7.

The building as designed exceeds the Passivhaus standard for Primary Energy by a bit over 50%.www.passipedia.orgwww.passipedia.orgSource: IG Passivhaus Osterreichwww.bruteforcecollaborative.comwww.millerhull.com93.657.5381610.534.7Passive House Consultantsnine-day intensive trainingexamcertified by PHIUSHow are they qualified?What do PH consultants do?run PHPPoptimize assembliesdevelop envelope detailsrecommend products & materialswww.bruteforcecollaborative.com~1,500 certified Passive House Consultants in the world.~200 in the US.~22 in WA State.A Different ParadigmConventional Approach(in a temperate area)Conventional Approach(in a cold area)Passivhaus(in a temperate area)Passivhaus(in a cold area)With Passivhaus on the other hand, the "furnace" stays the same (4.75 kBTU/SF/year), and the building envelope varies.With the conventional approach, the building envelope (insulation & windows) stays (more or less) the same and the size of the "furnace" varies to suit the heat loss.What will your choice be?Living Building ChallengeLike "passive solar," Passivhaus does gather and use the warmth of the sun to contribute to heating the building, and it does take into account shading to keep a building cool in summer, but in a Passivhaus you won't find Trombe walls, water walls (or much talk about thermal mass, really), or earth-berming or big expanses of south-facing glass to the exclusion of windows on other sides of the building.Passivhaus is probably the best way to get to net zero energy, because as you'll see, Passivhaus achieves a greater reduction in energy use than any other current approach--and that's *before* adding any active energy-generating systems.We'll come back to this building later, to compare its performance with Passivhaus.Before you continue, take a moment to click on "More" to the right of the forward arrow, and click on Full Screen. You can move forward and backward through the Prezi with the left and right arrows on your keyboard, and zoom in and out with the up and down arrows. OK!What will your choice be?What will your choice be?COMFORTDURABILITYSAFETYECONOMYpassive survivabilityenergy intelligenceHEALTHfresh air!GOALS OF PASSIVE HOUSE DESIGNA. Improved Comfort & Fresh Air -> PeopleB. Moving toward Carbon Neutrality -> PlanetC. Energy Reduction + Durability -> EconomyGermanyPassivHaus Apartments - Freiburg